PETpla.net Insider 10 / 2016

INSPECTION 27 PET planet Insider Vol. 17 No. 10/16 www.petpla.net Measuring thickness Despite robust practices that sup- port consistent bottle production, like the mandate never to mix different batches of preforms, Chimetto notes that blowmoulder performance is sus- ceptible to variation. Environmental conditions such as temperature and humidity are major factors that cannot always be controlled. For example, “big changes can occur around the blowing machine at night,” he says. “If other machines nearby are shut down, the tempera- ture can drop. There are also natu- ral temperature fluctuations with the weather. These temperature variations affect the blowing operation.” More than a decade ago, Chimetto looked to Agr for help in minimising the impact of these variations on the blowing process. As the relationship developed, he became an early adop- ter of a “take-no-chances, measure everything” approach to bottle-mak- ing. It started in 2003 with the installa- tion of Agr’s Profiler on-line thickness measurement system deployed inside the blowmoulder. The earliest Profiler systems used sensors to measure the material thickness in four different zones along the bottle sidewall, pro- viding feedback that allows the blow- moulder operator to better manage the blowing process. “This was a real benefit,” states Chimetto. “As soon as the operator made an adjustment, he could really see the effect. This eliminated a lot of guessing and especially the potential to make an adjustment in the wrong direction.” Having confirmed the valuable contribu- tion the Profiler made to its quality program, Sanpellegrino installed the device on several high-speed blowing lines (then as fast as 30,000bph) where material distribution was critical for bottle performance. The targeted sites included the Scarperia, Tus- cany, plant produc- ing the Acqua Panna brand; Cepina Valdisotto, in the Alps, for Levissima production; and San Giorgio in Bosco, in Padova (Padua), for the Nestlé Vera brand. Profiler’s non-contact, non- destructive measurement enhanced Sanpellegrino’s ability to achieve uniform production, meeting the same standards for shape, dimension, and clarity in every bottle. It also provided real-time process information, allow- ing operators to counteract the vari- able conditions the different blowing lines were subject to, saving produc- tion time and reducing scrap. “Without the Profiler, the opera- tor had to adjust, observe, test, and verify, and then re-adjust the process until it was right,” Chimetto explains. “With this new tool, the operator had immediate feedback to see whether the changes made were proper. Essentially, it eliminated the need to section-weight to manage the pro- cess.” Providing control Fast forward to 2009, a time when blowmoulder speeds were increasing, lightweighting initiatives began to pro- liferate, and Agr was preparing to roll out its next-generation management tool, the Process Pilot automated blowmoulder control system. Reflect- ing significant technology advances, the Process Pilot provides not only more comprehensive measurement of the entire bottle sidewall, but also control of the blowmoulder to continu- ously maintain the proper material distribution. Two key Process Pilot innovations - miniaturised sensors and sophisticated algo- rithms that determine optimal blowmoulder parameter adjustments - add a new level of precision to bottle-blow- ing. Outfitted with up to 32 sensors spaced at 12.5mm intervals, the system reads the actual bottle thickness meas- urements, compares the data with the speci- fied parameters, moni- tors the comprehensive measurements, and, as changes are identified, automatically adjusts the blowmoulder to continue optimum production. Chimetto immediately recognised the benefit of being able to monitor and manage material distribution in real time on the production line, with Pilot serving as a virtual operator. “This really was the technology that made it possible to close the loop in blowmoulder control,” he empha- sises. “I saw the potential to actually monitor the details of material distri- bution and take it one step further to automatically control the blowmoulder to make the necessary changes to manage the process.” Nestlé Waters Italy agreed to field-test the Process Pilot technol- ogy, and its Levissima plant became the first bottling operation in Europe to deploy the closed loop system. Test results showed that the system offered a number of benefits, including the ability to manage the blowmoulder to virtually eliminate the effect of process and environmental variables that impact bottle material distribution, thus reducing scrap and improving production consistency. At production speeds approaching 40,000bph, the processing window for lighter bottles narrows significantly.